Parents at a private school in Florida can now buy bullet-resistant insertable panels for their kids’ backpacks, a $120 feature that’s the latest in a line of security measures at schools nationwide.

Administrators at Florida Christian School — a non-denominational private school for students from preschool through high school in Miami — are offering the thin, binder-sized piece of ballistic armor that’s capable of stopping bullets from a .44 Magnum and .357 SIG directly from its website. Alongside metal detectors, surveillance cameras and emergency drills, the inserts are part of recent measures to prevent casualties in the event of an active shooter situation.

“It’s just a tool,” Georhge Gulla, the school’s head of security, told the Miami Herald. “I’d rather be prepared for the worst than be stuck after saying ‘Wow, I wish we would’ve done that.’”

Gulla started working at the school after the 2012 shooting at Connecticut’s Sandy Hook Elementary School, where gunman Adam Lanza killed 20 children and six staffers before killing himself. With nearly three decades of law enforcement experience, Gulla implemented a series of new security measures at the school, including sound-enabled surveillance cameras and active shooter drills, during which students are instructed to wear their backpacks on their chests.

“We want to protect our students’ center mass,” he told the Herald.

While conducting the drills with parents last year, Gulla met Alex Cejas, founder of Applied Fiber Concepts, which manufactures the panels. Cejas also has two children, ages 11 and 13, at the school. Cejas then agreed to arrange a custom order for any parents at the school who were interested.

“We thought, yeah, let’s offer it to anyone who wants it,” Gulla told the newspaper. “It’s not required. But if it gives you extra peace of mind …”

A school spokeswoman declined to comment on Tuesday to The Post when asked how many inserts had been sold.

Reaction to the bullet-resistant inserts has mainly been positive, with some parents wishing for a “different time, a different world,” Gulla said.

Bullet-resistant products in schools is not a new concept, Cejas said, with some appearing after the 1999 shooting at Columbine High School in Littleton, Colo., where Eric Harris and Dylan Klebold killed 12 students and a teacher before committing suicide. Another company, Bullet Blocker, reportedly saw sales of its bulletproof backpack surge from about 20 per week to roughly 10,000 after the Sandy Hook massacre.

More recently, an Oklahoma company in 2014 created a bulletproof blanket with backpack-like straps to be used by students to protect themselves during mass shootings or natural disasters. The creator of the $1,000 Bodyguard Blanket said he thought of the idea after a tornado killed 24 people in Moore, Okla., including seven children inside an elementary school.

But Kenneth Trump, an expert in school security, told the Herald that the partnership between the Florida Christian School and Applied Fiber Concepts is “highly unusual,” given that they’re not purchased by the school directly, like the bullet-resistant whiteboards recently bought by a school board in Minnesota. Trump said some schools are also getting “tunnel vision” when it comes to active shooters.

“You’re bypassing grade school and jumping straight to grad school before you mastered the basics,” Trump told the Herald.